[Nick Grant]

I've done 2 DIY green roofs on our dwellings plus a couple of sheds but it's too early to report on long term durability.

As an Ecominimalist I'm appologetic about our roofs which are an eco-cliche and I am sceptical about them being particularly green but I also don't see them as particularly unecological. Any building component that doesnt fail and trash the building gets ecopoints in my book!

What I have learnt practically, is that, not surprisingly, penetrations are the achiles heal for DIY. Also flat is easier than pitched.

We have used Hypalon (sp?), Butyl (flat wkshop roof, no penetrations) and Monarflex PE. All were factory welded to form a single sheet. For our house we used the PE and did the penetrations (Isokern chimney, 2 x Vellux, 2 x vents and 2 x downpipes) using monobond tape (like flashband).

It's OK but I am not 100% happy with our joins as the tape softens when hot so can creep if not weighed down.

Hot air welding would be better but needs proper kit and skill and Monarflex said they would use tape if they did it. I tried to get a local firm to do the welding but could only find people offering whole system with guarantee – peace of mind we didn't think we could afford at the time but might seem a bargain in hindsight!!!

I am enthusiastic about flat roofs with a dusting of pea gravel and compost planted with scattered clumps of sedum. Not too much weight, easy to do and look fine with just 5 clumps of plants whilst they get established – very Zen with the gravel backdrop but not up to heavy traffic unless you sandwich with plenty of geotextile.

Brian Richardson (Self Build Book, Segal Trust, AECB) used Butyl many years ago for his house and I think it was mostly OK but he did notice wood tar from chimney disolving the butyl and also wasps had made a hole in it.

Generally with proper detailing a green roof should last for ever as the liner is protected from sun and temperature extremes.

Robust roofing to cover our lovely thick eco insulation is a subject in itself and worthy of some serious consideration.

[Nick Grant]

We used Caithness flag with honed finish from A & D Sutherland. Wiped with veg oil 2 years ago. Bit like slate.

Not making any claims about the eco-ness but its a nice long life UK sourced stone that doesnt break the bank (but can't compete with Chinese granite!). Edinburgh is paved with it in natural riven form.

[Nick Grant]

When we wrote the EA fact cards there was just Hansa available but now there are a few including Armitage and B&Q. Only one I have experience of is Hansa which I got from Green Building Store but they now sell Kludi which I understand are same high quality and have the cold only middle position for energy saving (especially with combis).

Hopefully with time all single lever mixers will be like this but I expect quality will still vary.

[Nick Grant]

Don't expect to find the answers in a book!!!

The Pattern Language by Christopher Alexander and all is a classic whether you are building eco or otherwise.

[Nick Grant]

You can get it tested at a chemists (they supply a sample bottle and instructions). However first you need to assess the risk of contamination otherwise a one off sample is meaningless. There are good books eg Finding Water by Brassington 1995, Wiley but there is little substitute for experience and local knowledge.

Im too far away but if you give me a call I dont mind spending 5 minutes as will be easier than typing.

Nick, Elemental Solutions

[Nick Grant]

Because its a hobby horse of mine I just want to mention that, for the sake of argument, 90% of a building's environmental impact is during use not manufacture. ie if you want a green building dont get too hung up on sustainable materials if it means a compromise on energy efficiency.

Ideally you can get the look you want and energy efficiency whilst using funky green local materials but I see too many ecobuildings that leak like a sieve. Fine if you are happy to wrap in sheep skins and jump up and down to keep warm.

[Nick Grant]

Hi Vincent

Thanks for making the effort.

Webmaster notified of your screen issue but will need to know what browser and screen resolution you have. Works on my 17″ widescreen iMac and 12″ powerbook so not a size issue per se.

Re new forum for careers we do have a jobs offered and wanted with no posting yet so perhaps you could ask or offer advice there. If you want to rant then there is a forum for that.

Easy to add forums but makes it all more complex.

[Nick Grant]

I have reservations about this technology and would like to hear of experience and monitoring but am happy to accept that the energy would probably be paid back in a reasonable period.

However for me, the environmentally interesting question is could the same investment save more energy if invested in other areas such as efficiency or larger scale wind.

[Nick Grant]

Dan

I'm in over my head, had hoped some of the energy people would chip in!

When I said rig the vent I just meant jamming the shutter open a bit without the fan on if that is possible! (Shut the door so only bathroom gets cold) Only because you say there is no window or other vent. Variable speed only really possible with DC (low energy) fans or larger ac fans with special controller and I think that is OTT for what you describe.

If it is a damp old house with no insulation etc as I suspect then its a different situation to new build or well insulated and I'd tend to let plenty of air through and only try and heat it prior to a shower – that's what I grew up with – bathroom effectivly outside – no attempt to keep it warm all day.

Now I live in a warm dry house the Baxi makes sense for us and has worked fine for last 2 years. We chose the baxi because of the low power fan, especially on trickle. As I said b4 we don't dry wet towels in the bathroom though but then it isnt heated (unless the thermal store is over temp and the towel rail dump kicks in).

[Nick Grant]

Sorry Dan for my contribution to the complication. With the heat recovery I was thinking general damp reduction rather than just airing towels and quickly solving your specific problem.

How about a dual fuel electric/water towel rail for flexibility?

Can the extractor fan be rigged to give some trickle vent given lack of a window?

[Nick Grant]

I guess for a flat you will stick with combi when replacing otherwise if adding a storage tank I was thinking towel rail can come on even in summer when water heats say 2x per day or on own timer.

We have thermal store and wood/solar and a towel rail is only 'rad' we have. Comes on when tank is up to temp.

Lateral thoughts include drying towels outside bathroom and opening window in summer when heating off – is there a window?

My main reservation with electric towel rail would be if it was left on all the time (only a light bulb as manufacturers say! – 1.4kW.h/day), don't imagine any stat would cut out with only 60W input.

[Nick Grant]

Hi John, Happy New Year

I was going to mention that condensing dryers use mains water but you went on to say that!

I do have a few problems with justifying electrical appliances on the basis that they contribute to heating in winter.

A low tech solution that has worked for us for the last 7 years is a covered veranda which works great as an all weather drying area with loads of other uses. Wouldnt work in a wet fog but I don't remember this ever happening. Clothes come into the house cold but dry and just in need of airing. Our house is pretty tight so we don't want to bring wet stuff in – ie we dont live in a drafty farmhouse with Aga.

A higher tech solution that Peter Warm has used is a small Baxi mhvr vent in a drying/utility room used on 2W trickle mode.

I have heard of other solutions but only second hand so hope others will contribute re eg Swedish and German low enegy house parctice.

[Nick Grant]

Done!

My first bit of lobbying for years. Thanks for making it point and click easy.

[Nick Grant]

I stand corrected!

Just found a small leaflet in my files 'A life Cycle Assessment of Multi-Glazed Windows' from Nordan UK. Interesting in itself but also has references and leads that might be useful.

01452 311379

[Nick Grant]

Sorry no answer either but an elaboration on Chris' point. I am interested in designs that protect the dgu eg 2+1 and ventilated rainscreen facades with single layer on outside and dgu on inside so should last 'forever'.

[Author]

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